Difference between revisions of "Adipocytic tumours"

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'''Adipocytic tumours''' fall into the grouping ''[[soft tissue lesions]]'' and includes things that are very common (e.g. lipoma) and everything from benign to malignant.   
'''Adipocytic tumours''' fall into the grouping ''[[soft tissue lesions]]'' and includes things that are very common (e.g. lipoma) and everything from benign to malignant.   


This grouping includes a number of tumours, which can be divided based on their behaviour into ''benign'', 'intermediate'' and ''malignant''.
=Overview=
This grouping includes a number of tumours, which can be divided based on their behaviour into ''benign'', ''intermediate'' and ''malignant''.


Benign:<ref name=Ref_WMSP_601>{{Ref WMSP|601}}</ref>
==Benign==
Benign adipocytic tumours:<ref name=Ref_WMSP_601>{{Ref WMSP|601}}</ref>
*Lipoma.
*Lipoma.
*Angiolipoma.
*Angiolipoma.
Line 15: Line 17:
*Hibernoma.
*Hibernoma.


Intermediate:<ref name=Ref_WMSP_601>{{Ref WMSP|601}}</ref>
==Intermediate==
Intermediate adipocytic tumours:<ref name=Ref_WMSP_601>{{Ref WMSP|601}}</ref>
*Atypical lipomatous tumour.
*Atypical lipomatous tumour.


Malignant:<ref name=Ref_WMSP_601>{{Ref WMSP|601}}</ref>
==Malignant==
Malignant adipocytic tumours:<ref name=Ref_WMSP_601>{{Ref WMSP|601}}</ref>
*Dedifferentiated liposarcoma.
*Dedifferentiated liposarcoma.
*Myxoid liposarcoma.
*Myxoid liposarcoma.
Line 25: Line 29:
*Liposarcoma NOS.
*Liposarcoma NOS.


=Detail section=
==Lipoma==
==Lipoma==
===General===
===General===
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*Reticulin ???.
*Reticulin ???.


==See also==
=See also=
*[[Soft tissue lesions]].
*[[Soft tissue lesions]].
*[[Bone]].
*[[Bone]].


==References==
=References=
{{Reflist|2}}
{{Reflist|2}}


[[Category:Soft tissue lesions]]
[[Category:Soft tissue lesions]]

Revision as of 17:43, 8 April 2011

Adipocytic tumours fall into the grouping soft tissue lesions and includes things that are very common (e.g. lipoma) and everything from benign to malignant.

Overview

This grouping includes a number of tumours, which can be divided based on their behaviour into benign, intermediate and malignant.

Benign

Benign adipocytic tumours:[1]

  • Lipoma.
  • Angiolipoma.
  • Myolipoma.
  • Pleomorphic lipoma.
  • Lipomatosis.
  • Lipomatosis of nerve.
  • Lipoblastoma.
  • Extrarenal angiomyolipoma.
  • Extra-adrenal myelolipoma.
  • Hibernoma.

Intermediate

Intermediate adipocytic tumours:[1]

  • Atypical lipomatous tumour.

Malignant

Malignant adipocytic tumours:[1]

  • Dedifferentiated liposarcoma.
  • Myxoid liposarcoma.
  • Pleomorphic liposarcoma.
  • Mixed-type liposarcoma.
  • Liposarcoma NOS.

Detail section

Lipoma

General

Microscopic

Features:

  • Collection of mature adipocytes.
    • Variation of size may be seen -- should prompt a search for lipoblasts.[2]

Notes:

  • Microscopically not definitely distinguishable from mature clump of fat.
    • The lesion must be labeled lipoma to be signed-out as such.

Pleomorphic lipoma

General

  • ???

Microscopic

Features:

  • Multinucleated cells - "floret cells".
    • Very ugly looking cells.
  • Fibrous septa.

Image: Floret cells in a pleomorphic lipooma (pathconsultddx.com).[3]

Notes:

  • May overlap with spindle cell lipoma.[4]

Hibernoma

General

  • Consists of brown fat (present in the infants to generate heat).[5]
  • Benign.
  • Usually asymptomatic.[6]

Epidemiology

  • Young adults.

Gross

  • Well-circumscribed.
  • Lobulated and light-brown on sectioning.

Microscopic

Features:[7]

  • Large polygonal/oval cells:
    • Nucleus - central & small.[8]
      • Nucleoli typically prominent.[9]
    • Cytoplasm - multivacuolated, oval, eosinophilic, granular.

Image:

Atypical lipomatous tumour

  • AKA well-differentiated liposarcoma, abbreviated WDLPS.
  • Abbreviated ALT/WDLPS.

General

Microscopic

Features:[10]

  • Large adipocytes.
  • Atypical lipoblasts - focal, scattered:
    • Nuclear hyperchromasia.
    • +/-Multinucleated.

Liposarcoma

  • Most common malignant sarcoma in the retroperitoneum.

Microscopy

Features:

  • Lipoblasts:
    • Large sharply demarcated vacuole.
    • Nucleus:
      • Hyperchromatic (dark staining) nucleus.
      • Eccentric location.
      • Nuclear indentation.

Images:

Subtypes

There are several subtypes:[1]

  • Dedifferentiated liposarcoma.
  • Myxoid liposarcoma.
  • Mixed-type liposarcoma.
  • Pleomorphic liposarcoma.
  • Liposarcoma not otherwise specified (NOS).

IHC

  • IHC is of limited value.
  • S-100 +ve ~1/3 of the time.
  • Reticulin ???.

See also

References

  1. 1.0 1.1 1.2 1.3 Humphrey, Peter A; Dehner, Louis P; Pfeifer, John D (2008). The Washington Manual of Surgical Pathology (1st ed.). Lippincott Williams & Wilkins. pp. 601. ISBN 978-0781765275.
  2. PMID 8548119.
  3. URL: http://www.pathconsultddx.com/pathCon/diagnosis?pii=S1559-8675%2806%2970321-7. Accessed on: 4 December 2010.
  4. URL: http://surgpathcriteria.stanford.edu/softfat/spindle_cell_lipoma/. Accessed on: 4 December 2010.
  5. Humphrey, Peter A; Dehner, Louis P; Pfeifer, John D (2008). The Washington Manual of Surgical Pathology (1st ed.). Lippincott Williams & Wilkins. pp. 605. ISBN 978-0781765275.
  6. Ahmed SA, Schuller I (December 2008). "Pediatric hibernoma: a case review". J. Pediatr. Hematol. Oncol. 30 (12): 900–1. doi:10.1097/MPH.0b013e318184e6dd. PMID 19131775.
  7. Chen DY, Wang CM, Chan HL (March 1998). "Hibernoma. Case report and literature review". Dermatol Surg 24 (3): 393–5. PMID 9537018.
  8. http://www.pathconsultddx.com/pathCon/diagnosis?pii=S1559-8675(06)70271-6
  9. http://surgpathcriteria.stanford.edu/softfat/hibernoma/
  10. Humphrey, Peter A; Dehner, Louis P; Pfeifer, John D (2008). The Washington Manual of Surgical Pathology (1st ed.). Lippincott Williams & Wilkins. pp. 605. ISBN 978-0781765275.